Abrading machine



May 28, 1935.

c. JOHNSON ABRADING MACHINE,

original Filed Aug. 15, 1930 v 3 Sheets-Sheet 1 I May 28,- 1935. c. JOHNSON 2,002,665

ABRADING MACHINE Original Filed Aug. 15, 1950 3 Sheets-Sheet 2 May 28, 1935- c. JOHNSON BRADING MACHINE original Filed Aug. 15, 195o 3 Sheets-Sheet 5 67307165 Jail/726.071), a, M Mw @i the desired Another object is to provide a new and 1m- Patented May 28, 1935 UNITED. STATES tion of Illinois "invention relates generally to an abradin'g ii'xachine and more particularly to a machineffor abrading and polishing or finishing matri sheet form.

'I'he preferred form of the invention as illusinnthe accompanying drawings and deliereinaftcr is particularly adapted for n" abradin and polishing extremely hard metal l ordinary'forms of abrading machines have beenV foundwfineifective and heretofore special machinesv'which have ybeen constructed for this workhave .been cumbersome and expensive and haverrequied agreat deal of time in obtaining ilnish.

- `The-f general object of this invention is to provides.' new and improved abrading machine for'iinishing and polishing extremely hard material insheet form.

proved `"abrading machine embodying an endless abrasive `belt together with means for supporting aV sheet =of` material and means for flexing the belt into'engagement with the work sheet during @g relative; -movement between the flexed portion of` theribeltfr and the sheet, so that the entire sheeirmay` be finished. I

Another object is to provide an abrading machinevzforhard sheet materials embodying an 1 endless` abrasive belt, a support for the work sheetands-'means reciprocating along one run off-theabelt embodying means for flexing the belt :intofcontact with the sheet around a curved surfacexfhaving a relatively short radius.

\.-,\;;'Be'causez.of the extreme hardness of the metal (if-f itx'is'necessary to apply considerable pressure to thezaabradant in order to obtain the desired aotion. .1 -'This causes considerable heat which has attendencyy to buckle the metal. 'It is therefore y an'a'obiectiof the invention to provide a novel PATENT OFFICE ABBADING MACHINE Charles Johnson, Rockford, lll., aaaignor to Mattisch Machine Works, Rockford. Ill., a corpora Application August l5, 1930, Serial No. 475,569 f Renewed February l5, 1934 zo claim. (ci. 51-135) support so that the abrasive means may nish the sheet all the way to its side edges. In this manner there is no wastage of material, the entire surface being nished.

Another object of the invention is to provide 5 an abrading machine embodying a work support, reciprocatory abrasive means movable across said work support and a pair of roller means extending along opposite edges of the path of contact of said abrasive means on a work sheet l0 and engaging the work sheet to hold it down on thev work support while permitting transverse movement of the work support.

Further objects and advantages of the invention will become apparent as the description pro- 15 ceeds.

In the drawings:

Fig. l is a front elevational view of a pre ferred form of the invention.

Fig. 2 is an enlarged fragmentary view of the 20,

reciprocating abrasive means.

Fig. 3 is an enlarged fragmentary section substantially along the line 3 3 of Figs. l and 2.

Fig. 4 is a fragmentary front elevational view of another form o'f the invention embodying 25 automatic means for reciprocating the work support transversely of the belt.

Fig. 5 is a transverse section approximately along the line I-S of Fig. 4.

Fig. 6 is la fragmentary plan view of the left 30 hand end of Fig. 4.'

While the invention is susceptible of embodiment in many different forms, I have shown in the dra-wings and shall herein describe in detail one such embodiment and a modified form 35 thereof `with the understanding that the present disclosure is to be considered as' an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. 'Ihe scope of the inven- 40 tion will be'pointed out in the appended claims.

In the exemplary form illustrated in the drawings, the invention'is disclosedas embodied in a machine of the general type shown in Patent No. 1,478,044 to C. L. Mattison dated December 45 18, 1923. Generally this machine has a base or frame comprising a pair of uprights or pedestals 5 connected by a lower cross member 6. and an upper cross' member 1. Means including a pair of pulleys 8 and 9 rotatably mounted 50 on the frame is provided for supporting and driving an endless abrasive belt I 0. Preferably one of the pulleys such as 8 is driven by suitable means from an adjacent motor Il. The

work W is arranged to be carried on a support 55 -fully illustrated in said prior patent.

or table I2 which is positioned intermediate the uprights 5 and mounted for movement transversely of the belt by means of a plurality of 'rollers or wheels I3I operable o n a pair of rails I4. These rails are carried on a pair of. vertically adjustable slides I5. Preferably these slides may be raised and lowered simultaneously by means of vertical screws I6 (Fig. 4), which are rotatably mounted on the pedestals 5 and engage suitable nuts I'I on the slides, and are operable simultaneously by means including pairs of bevel gears I8 and a longitudinally extending shaft I9 which is formed at one end for receiving a suitable wrench or tool.

For applying the abrasive belt to the Work supported on the table I2, the machine embodies a vertically movable horizontally extending guide bar 20 supported by means of a plurality of arms 2|, rods 22 and 23 and brackets as more On this guide bar is supported a longitudinally movable means 25 which is arranged to be reciprocated by means including 'a tape or band 26,

secured at its opposite ends to the peripheries of a pair of pulleys 21, oscillating gear segments 26 which engage pinions 29 on the shafts of thepulleys 21, a rod 30 connecting said gear segments and a crank (not shown) having alpitman 3|, for oscillating the gear segments. Since this mechanism is disclosed in detail in said prior patent vthe accompanying drawings illustrate only generally the construction of the parts.

Due to the hardness of the sheet material which is to be finished, it has been foundr that the reciprocating shoe structures such as are found in the prior art machines adaptedl for wood and other relatively soft materials, are wholly unsuited. The failure of these prior mechanisms was due principally to the fact that the means employed for applying the abradant to the work did not utilize the abrasive properties of the belt to-the greatest extent, with the result that the belts would wear out quickly and without producing the desired nish on the work.

I have discovered that by flexing the belt around a curved surface of relatively short radius and into contact with the metal sheet so that only a' relatively short portion of the belt is in contact with the sheet there is a tendency to project the abrasive particles on the belt into a more efficient contact with the metal and to separate adjacent abrasive particles so that independently they act upon the metal. Thus instead of the rubbing action obtained when the belt is applied.by means of a at presser member there is an eflicient cutting action which results in a far quicker abrading of the sheet to the desired degree of finish or polish. Such rapid and eflicient cutting action is of particular importance in the finishing of sheets of stainless steel since this material is extremely' hard and the surface thereof must be abraded to a considerable depth to eliminate pits which are inherent in sheets of the material.

It has been found in practice that the flexing of'y a relatively short portion of the belt also serves to discharge foreign matter such as loose particles of the abraded material, loose or excessively worn particles of the abradant, and the loosened particles of adhesive. By reason of this positive discharging of the foreign matter caused by the positive and sharp flexing of the belt, the formation of a non-abrasive glazed surface on the belt is prevented. In addition to this, this improved actiony of the belt on'the downwardly from the frame member 35"and is bifurcated in form so as to provide longitudinally spaced portions 40 and 4I in which pulleys 42 and 43 are rotatably mounted; Inter-A mediate the portions 40 and 4I, a support 44 is mounted on a longitudinally extending pivot 45 and carries a pulley 46, the belt I0 passing over the pulleys 42 and 43 and under the p ulley 46 as illustrated most clearly in Figs. 1 and 2.

The pivotal mounting for the support 44 for the pulley 46 permits this pulley to aline itself automatically with the upper surface of the work sheet on the table I2 as illustrated most clearly in Fig. 3. The pulley is rotatably mounted by means of ball bearings 50 on a shaft 5I and preferably the pulleys 42 and 43 are similarly mounted on shafts 52 and 53.

I'he pulleys carried on the reciprocating means serve as a means for exing the` adjacent run of the belt into contact with the work. The central pulley 46 is preferably laminated in form as shown in Fig. 3 and comprises a'plurality of disks 54 of felt or other flexible material secured between metallic end members 55. This provides a pulley slightly yielding in character for effectively applying the belt to the work uniformly. The pulleys 42 and 43 serve as a means for maintaining the belt in contact with a substantial portion of the periphery of the laminated pulley 46 and are preferably provided with soft rubber rims 56 since they contact with the side of the belt carrying the abrasive material.

As mentioned hereinbefore, the finishing of extremely hard metal requires that the abrasive be applied with a considerable amount -of pressure. This tends to cause local heating of the sheet and even buckling thereof unless efficient means is provided ,for preventing lthe buckling. The invention provides novel mechanism for preventing buckling. As illustrated herein, this means is in the form of roller means comprising a pair of rolls 60 and4 6I extending longitudinally of the belt I0 and spaced laterally as shown in Fig. 3 so as to contact the work sheet along the edges of the path `of movement of the pulley 46, or in other words along the longitudinal edges of the abrading zone. These rolls are rotatably mounted on a pair of brackets 62 secured to and extending forwardly from the pedestal portions 5 yof the frame. In this way, the pressure of the rolls upon the work sheet may be adjusted by means of the screws I6 which are provided for raising and lowering the table I2.

Cooperating with Ithe hold-down means for preventing buckling of the. sheet, the invention preferably provides the table I2 with a plurality of heat radiating webs or fins 63` extending longitudinally thereof as shown best in Figs. l, 3 and 5. The table is preferably of cast iron and the hold-down rolls and these fins lseparately or cooperatively serve as a means for preventing buckling of the sheet, the rolls maintaining the sheet in contact with the table along the abrading zone and the ns effectively dissipating the heat generated.

This hold-down means serves not lonly to hold down the sheet of metal along the zone in which the abradant is applied so as to prevent any buckling, but also serves to clamp the sheet to the table and prevent movement of the sheet relatively to the table. In this lattercapacity it will be apparent that the hold-down roller .means are particularly efcient in that they contact the sheet along the sides of the path of the pulley 46 and therefore permit the reciprocating abrasive means to contact the work all the way to the ends of the sheet.

Furthermore the roller means permit transverse movement of the table and during such movement maintain a zone of constant width upon which the abrasive vmeans operates and also maintains a constant pressure on the sheet for clamping it to the table. The hold-down means therefore permits the table to be moved transversely so that the abrasive means may finish the entire surface of the sheet all the way to the side edges, a single roll serving to hold the sheet down while the extreme edges are being finished. In this way there is no waste of material, since the entire surface is finished. This is obviously true whether the sheet be rectangular in form or of any other shape.

The invention preferably provides automatic or power driven means for reciprocating the work support I2, such means being herein disrails I4 which are supported on vertically adjustable slides I5. Preferably the forward ends of the rails I4 are supported by means of'adjustable pedestals 14.

The mechanism for reciprocating the work support is herein disclosed ascomprising a rotatable drum mounted on a shaft 18 on a frame 11 positioned beneath the work support. A cable 18 is wound around the drum a plurality of times and has its opposite `ends secured to a pair of brackets 19 and 80 as indicated most clearly in Fig. 5, said `brackets extending down-y wardly from and being carried by the central transverse I beam 13. Thus by rotating the drum in reverse directions. the table will be reciprocated due to the winding and unwinding of the cable on and from the drum.

The means for actuating the drum 15 is herein shown as comprising a Worm wheel 8| on the shaft 18, a worm 82 engaging the worm wheel, a transversely extending shaft 83 for the worm, a cone pulley 84 on the front end of the worm shaft 83, an electric motor 85 having a complementary cone pulley86, and a belt 81. The electric motor is arranged to be controlled by means including ya drum type switch 88 which is supported on the left hand slide I5 (Fig. 4) with its operating arm 89 positioned adjacent the left hand edge of the work supporting structure. switch may be of any preferred construction having an operating arm with two operative positions, one as shown in Fig. 6 in which position of the switch the motor 88 would be operated to actuate the work support downwardly in saidflgure, and a second lower poddrum switch-arm 88 and shift said arm to reverse the motor 85. Similarly at the rearward end of the work support movement, a dog 8l is arranged to engage the drum switch arm 88 to again reverse the motor. The dogs88 and 8| are preferably mounted adjustably upon the left hand end member 1I (Fig. 4) so as to permit of varying the stroke of the work support trans-l versely of the belt.

l In its preferred form the invention also provides means for collecting the dust resulting from the abrading action. As illustrated herein the left hand portion 48 (Figs. 2 and 3) of the reciprocating means 25 is hollow and has a plate 82 across its lower end so as to substantiallyenclose the pulley 42. A slot 88 is provided across the portion 40 adjacent the right hand end of the said plate (Fig. 2) so that with the pulley 48 operating in a clockwise direction, the dust will be thrown into the portion 40 through said slot. This collecting of the dust is facilitated by providing a discharge opening 84 for the enclosure and connecting said opening to a suitable suction system. It will be noted that' since the belt I0 rises sharply from the pulley 48 along the portion 40 the intake slot 83 may be positioned close to the point of contact of the belt with the work W. i In operation a work sheet is positioned on the table I2 and the table then raised until the hold-down means 68 and 8| contact the work with the desired pressure. Then the reciprocating means for the abrasivel belt may be lowered so that the belt contacts the upper surface of the work with the desired pressure. During reciprocation of the abrasive means the table I2 may be moved transversely so that the entire work sheet will be finished. By varying the coarseness of the `abrasive means on the traveling belt the desired nish can be obtained.

I claim as' my invention:

1. A machine having, in combination, a frame comprising a pair of laterally spaced pedestals,

an abrasive belt, means including rotatably mounted pulleys for supporting and driving said belt, slides movable vertically on said pedestals,

means for adjusting said slides, transversely extending rails carried on said slides, a work table movable on said rails transversely of the frame, means for applying the belt to a work piecev on said table comprising means reciprocating longitudinally on said frame embodying means to flex the belt into engagement with the work, and means for moving the table transversely, and means to prevent buckling of the work sheet comprising means for holding down the work sheet embodying brackets extending forwardly from said pedestals and a pair of rolls rotatably mounted in laterally spaced parallel relation on said brackets so as to engage the work sheet along the sides of the belt and means beneath the table for dissipating heat generated by the abrading action.

2. A machine having, in combination, a frame, an abrasive belt, means including rotatably table mounted pulleys for supporting and driving said belt, a work table movable transversely of the frame, means to apply` the belt to a work piece on said table comprising means reciprocating longitudinalb'r onlsaid frame embodying means to ilex the belt into engagement with the work and means for moving the table transversely, and means to prevent buckling of the work sheet comprising means for holding down the work, sheet embodying a pair of roller means mounted in laterally spaced parallel relation on said frame so as to engage the work sheet along the sides of the belt and means beneath the table for dissipating heat generated by the abrading action.

3. A machine having, in combination, a frame, an abrasive belt, means including rotatably mounted pulleys for supporting and driving said belt, slides movable vertically on said frame, means to adjust said slides, transversely extending rails carried on said slides, a work table on said rolls transversely of the frame, means to apply the belt to a work piece on said table comprising means reciprocating longitudinally on said frame embodying means to flex the belt into engagement with the'work and means for moving the table transversely, and means to hold down the Work sheet comprising brackets extending forwardly from said pedestals and a pair of roller means mounted in laterally spaced parallel relation on said brackets so as to engage the work sheet along the sides of the belt.

4. A machine having, in combination, a frame, .an abrasive belt, means including 'pulleys for supporting anddriving said belt, a work table slidable on said frame transversely of said belt, means to apply said belt to a work piece on said including longitudinally reciprocatory means for flexing the belt into contact with the work, means for moving the table transversely,

and means for holding the work down on the table including a pair of rolls rotatably mounted on said frame and engaging the -work along the sides of the path of contact of the -belt with the Work.

5. A machine having, in combination, a frame, an abrasive belt, means including pulleys for supporting and driving said belta work table slidable transversely of saidy frame, means to apply said belt to a work piece on said table including reciprocatory means for flexing the belt into contact with the work, means for holding the-work down on the table including a pair of rolls rotatably mounted on said frame and engaging the Work along the sides of the path of contact of the belt with the work and means for preventing buckling of the work sheet including said hold down means.

6. A machine comprising, in combination, a frame, an abrasive belt, a work table slidable transversely of said frame, means to apply said belt to a work piece on said table including reciprocatory means for flexing the belt into contact with the work, and means for holding the work down on the table-including a pair of rolls rotatably mounted on said frame and engaging the work along the sides of the path of contact of the belt with 'the work.

7. A machine having, in combination, an abrasive belt, means including pulleys for supporting and driving said belt, reciprocatory meansfor flexing the belt intoicontact with the work comprising a reciprocating carrier, a pair of laterally spaced rollers mounted on said carrier and over-which one run of the belt passes,

and an intermediate lroller mounted on said carrier and .under which the belt passes into contact with the work.

8. vA machine of the character described having, in combination, a frame, an abrasive belt, means for supporting and driving the belt, a work table movable transversely of the belt, and means for holding a work sheet down on said table comprising a, pair of rotatably mounted rolls positioned in laterally spaced parallel relation and contacting the work sheet along opposite edges of said belt.

9. A machine'of the character described having, in combination, a frame, a work table movable transverselyon the frame, abrasive means on said frame arranged tomove longitudinally of the table in engagement with the work, means for moving said table transversely and means for holding down the work on the table comprising `a pair of laterally spaced longitudinally extending roller means mounted on said frame and engaging'the work along the sides of the path of said abrasive means.

10. A machine tool having, in combination, a frame, a work table slidable transversely on said frame, a pair of laterally spaced longitudinally extending rolls rotatably mounted on said frame arranged to engage and hold down a work sheet on said table and permitting transverse movement of the table, said rolls defining a narrow strip of the worksheet therebetween on which an abrasive means may be applied, longitudinally reciprocating means for applying an abrasive means to the sheet intermediate the rolls, and means for reciprocating said table transversely during longitudinal reciprocation of said abrasive means.

11. A -machine having, in combination, a frame, a transversely movable work table and means for holding down a sheet of material on said work table comprising a pair of laterally spaced longitudinally extending rolls rotatably mounted on said frame arranged to engage said sheet and hold down the sheet and vprevent longitudinal movement thereof without obstructing the end portions of the sheet, and means moving longitudinally on said frame intermediate said rolls arranged to operate on said sheet, said table being movable transversely during said longitudinal movement to permit said operating means to contact the entire adjacent surface of the sheet.

12. A machine tool having, in combination, a frame comprising a pair of laterally spaced vertically positioned pedestals, slides movable vertically on adjacent faces on said pedestals, means for adjusting said slides, a pair of transversely extending rails carried one on each of said slides, a work table slidably mounted on said rails, a pair of brackets, one extending forwardly from each of said pedestals, a pair of rolls rotatably mounted between said brackets in laterally spaced parallel relation and arranged to hold down a (work sheet positioned on said table and means movable longitudinally of said table intermediate said rolls for operating on the work sheet.

13. A machine tool having, in combination, a frame comprising a pair of laterally spaced verticallypositioned pedestals, slides movable ver-v said slides, a work table slidably mounted on said rails, a pair Vof brackets one extending for- Iing through which the dust resulting from the wardly from each,of said pedestals, a pair oi! rollers rotatably mounted between said brackets inl laterally spaced parallel relation and arranged to hold down a Work sheet `positioned on said table, an endless abrasive belt, means including pulleys for mounting and driving said belt with one run thereof passing above said table between said rolls and means mounted on the'frame and slidable longitudinally thereof arranged to apply said belt to the work sheet intermediate the rolls.

14. A machine of the character described having, in combination, a -pair of laterally spaced hold-down roller devices mounted on stationary axes, a work support adjustable toward and from a plane passing through said axes, an operating mechanism adjustable toward and from said devices and work support and also reciprocatory parallel to and between said holddown devices.

15. An abrading machine having, in combination, an abrasive belt, means including pulleys for mounting and driving said belt and a 4reciprocatory structure for exing said belt into contact with the work comprising a pair of laterally spaced rotatably mounted guide pulleys over which one run of the belt passes, a transversely swingable support positioned intermediate said guide pulleys and a pulley rotatably mounted on said support engaging the belt and ilexing it beyond said guide pulleys, said" last mentioned pulley being laminated in form and comprising a plurality of disks of iiexible material, and a housing substantially enclosing the guide pulley' over which the belt passes from said intermediate pulley and having an opening through which the dust resulting from the abrasive action may pass, said opening being positioned closely adjacent the point of contact of the belt with spaced rotatably mounted guide pulleys overwhich one run of the belt passes, a pulley rotatably mounted intermediate said guide pulleys and engaging the-belt and flexing it beyond saidguide pulleys, and means substantially enclosing the guide pulley over which the belt passes from said intermediate pulley and having an openabrasive action may pass, said opening being positioned closely adjacent the point of contact of the belt with the work.

1'7. An abrading machine having, in combination, an abrasive belt, means including pulleys for mounting and driving said belt and a reciprocatory structure for flexing said belt into contact with the work comprising a pair of laterally spaced rotatably mounted guide pulleys over which one run of the belt passes, and a pulley rotatably mounted intermediate said guide pulleys and engaging the belt and flexing it beyond said guide pulleys.

18. An abrading machine having, in combination, a vdriven abrasive belt, and a reciprocatory structure movable across the face of a piece of work for exing said belt into contact with the work including triangularly arranged guide elements speced relatively closely together and only one of which is adjacent to the work, said belt being passed over the side of said adjacent element next to the work and over the sides of the other elements remote from the Work whereby s'aid adjacent element bends the belt sharply for contact with the work.

19. A machine of the character described comprising, in combination, an endless work performing belt, reciprocatory means having a path of movement along and adjacent to a piece of work, means for driving said belt, a plurality of rotatable members engaging andoperatively supporting said belt including a pair of spaced members mounted on said reciprocatory means and over which said belt passes, and an intermediate member under which the belt passes and by which the belt is flexed into contact with the work,

20. In a machine of the character described, the combination of a work support having a `work engaging face adapted to support a lsiz- 

